After the Breakup, M works

Chapter 99

    

lding his sister's face in his hands, earnestly saying something to her.His eyes flashed with displeasure, and he quickened his pace. Before he could get close, they had already gotten into their car...Chapter 99

"One can know a person's face but not their heart."

What is the meaning of this strange text: >>

"So, you dug the hole for her knowing this would happen...No matter what, you'll end up calling the police in the end!"

Remember for one secondChapter 606